Help! I think my IUD is doing more bad than good..

i have the lilleta, i think thats how you spell it, lol.. but it's just horrible.. ive almost had it for two years now, and it hasn't really given me a break with the cramps, irregular periods (if i even have one a month) like ill go two months without one and the next month ill bleed for the whole month or at least to weeks.. and after sex its worst feeling. i went a week after year bc i thought it had moved thats how bad it was hurting, and the obygn said it just hadn't settled with my body yet.. which is crazy.. i just don't know what to do.. im 18 with no kids.. please help..